Traffic actuated control apparatus



March 15, 1966 c. 1.. cu VIVIER TRAFFIC ACTUATED CONTROL APPARATUS 5 SheetsSheet 2 Filed May 9, 1960 FIG. 2

INVENTOR. CHARLES L. DU VIVIER ATTORNEY E 2 3 2 3 2 223 LC A A B B C DEE AM I z 1 2 h WW A A B B C D E E m March 15, 1966 c. 1.. DU VIVIER TRAFFIC ACTUATED CONTROL APPARATUS 5 Sheets-Sheet 5 Filed May 9. 1960 R m mw TN V U m0 L s E .L R A H c m I I I2:- 8 vm Y G W N-W Y 0 S S S 6 IN mm 0 6 9 6 I B r 4 M 4A 56 mm 4 m w n 4A6 9 w. W m m 4 i v 5 0 r 5 P D B m P 8 I 3 1 L W m .6 P G L I O .um-n w All. 6 1 5 l D o m m ll B H 2 5 O l G ATTORNEY March 15, 1966 c, u vlViER 3,241,106

TRAFFIC AGTUATED CONTROL APPARATUS Filed May 9. 1960 5 Sheets-Sheet 4 J k T LANE L22 Y LANE L33 DISPLAYED TO DISPLAYED To msouwo TRAFFIC OUTBOUND TRAFFIC F G. 9 INVENTOR.

CHARLES L. DU VIVIER dlo? 5.1.141

ATTORNEY March 15, 1966 c. L. DU VIVIER TRAFFIC ACTUATED CONTROL APPARATUS 5 Sheets-Sheet 5 Filed May 9, 1960 INVENTOR. CHARLES L. DU VWIER Z4424 Z! M ATTORNEY mmm mm ma tuw wmmmvmmm MN New MNN l mmmmmmmm gm EN In w United States Patent O 3,241,106 TRAFFIC ACTUATED CONTROL APPARATUS Charles L. Du Vivier, Darien, Conn., assignor, by mesne assignments, to Laboratory for Electronics, Inc, Boston, Mass, a corporation of Delaware Filed May 9, 1960, Ser. No. 27 ,605 9 Claims. (Cl. 340-36) This invention relates to traffic actuated control apparatus or systems, and more particularly to apparatus for automatic reversal of the right-of-way of directional flow of trafiic over one or more lanes of a rnulti-lane street, roadway or the like, in response to traflic conditions as obtained by a sampling of such tratiic conditions by trafiic actuation.

From one aspect the invention relates to improved apparatus for the selection of an oil-center traffic flow between two directions along the same roadway in response to trafiic actuation by traffic flowing in the respective directions along such roadway, as for example, inbound and outbound traffic.

From another aspect the invention relates to an improved control system for varying the number of lanes for opposite directions of traffic along a multi-lane roadway, allocation of a reversible lane or lanes being made to the direction of trafiic flow having the heavier or predominating traffic as determined by sampling of the respective traflic flows in opposite directions along the controlled roadway. The reversible lane or lanes may also be placed on a neutral basis without assignment to either one direction in response to substantially balanced trafiic in opposite directions along the road or in case there is no substantial predominance of tratlic in one direction over the other.

DISCUSSION OF PRIOR ART The off-center or unbalanced allocation of road width for bi-directional trafiic along a multi-lane street or roadway, as by two lanes in one direction and one lane in the opposite direction, for example, has been employed previously to expedite rapid movement of unbalanced traflic, i.e. traflic substantially heavier in one direction than in the other direction on the same street or roadway.

It is well known in the field of trail-lo control to reverse as desired, the direction of trafiic flow, along center lanes of a multi-lane roadway serving bi-directional traffic, thereby alternating the off-center trafiic movement between the two traflic flows, as desired. It is also already lcnown to have the center lane neutral or not allocated exclusively to either direction for periods of substantially balanced traflic.

A paper entitled Reversing Flow in Center Lane of 3-Lane Roads by Melville M. Todd, appearing on pages 29 to 37 of the 1949 Proceedings of the Institute of Traflic Engineers at New Haven, Connecticut, copyright 1949, is one of several articles published on the subject of control of a reversible lane of a multi-lane roadway.

An article, Unbalanced Trafiic Flow on Three or Four Lane Streets, by Joseph F. Rice appearing on pages 137 to 153 of Trafiic Quarterly of January 1956 published by the Eno Foundation for Highway Trafiic Control, Inc. at Saugatuck, Connecticut, copyright 1956, also discusses the subject of control of reversible lanes of a multi-lane bi-directional roadway. At the end of Joseph F. Rices said article is a bibliography in which are listed other articles on the same subject.

A paper entitled A Trafiic Actuated Cycle and Offset Selector System by John L. Barker, development engineer for Automatic Signal Division of Eastern Industries, Incorporated, Laboratory for Electronics, Inc., the assignee of the present invention, appears on pages 70 3,241,19 Patented Mar. 15, 1966 to 76 of the aforementioned 1949 Proceedings" and mentions Mr. M. M. Todds paper.

Mr. Barkers paper relates to several aspects of signal systems providing for non-preferential treatment or preferential treatment for traflic flow in opposite directions along a road, for example, in response to relative tr-afiic demand in such directions. Mr. B arkers US. Patent 2,542,978 issued February 27, 1951, for Trafiic Actuated Control Apparatus, and assigned to the assignee of the present application, presents some examples of systems and apparatus relating to non-preferential and preferential directional control of trafiic how in respect to comparative actuation in the respective directions as more fully set forth in said patent.

The interrelated French Patents 992,198 and 992,202, delivered July 4, 1951, both are examples of prior art relating to allocation of a reversible central traffic lane of a roadway to one or the other direction or to a neutral condition in response to traffic actuation to vary the number of lanes allocated to the respective opposite d-irections in accordance with relative tratfic demand in the respective directions.

SEVERAL ASPECTS OF THE PRESENT INVENTION From one aspect the present invention is a greatly improved lane changing or reversing system and apparatus, including vehicle detection devices for detecting vehicle traffic of the respective flows of traffic in opposite directions on a roadway, traflic measuring devices for the respective flows of trafiic, a comparison device or controller that determines the relation between the measurement of the two directional traific flows as presented by the trailic measuring devices, one or more master lane changers, responsive to the controller, and one or more local lane changers associated with and responsive to each master lane changer for control of the direction of tratfic flow through selective signal indications, in one or more traffic lanes jointly or individually, of a multi-lane roadway.

Within the present greatly improved lane changing system and apparatus is the inclusion of certain novel components as part of the trafiic measuring devices. By employing multiple vehicle detectors in the respective trafiic measuring devices, with the vehicle detectors individual to each lane as well as individual to each direction of potential 'trafiic flow in the lane, certain of the vehicle detectors are automatically selected and connected to an associated counting or measuring unit according to the direction of traflic permitted in the lane in which the vehicle detector is located.

Alternate selection apparatus for vehicle detection, in cluding vehicle detectors individual to each lane but common to each direction of potential trafiic flow in the lane, and the channeling of the detection impulse to a selected counting or measuring unit in response to the master lane changer and according to the direct-ion of trafiic permitted in the lane in which the vehicle detector is located, is also offered as another means by which an accurate representation of vehicle traliic on the roadway may be obtained.

Still another alternate selection apparatus including vehicle detectors individual to each lane and common to each potential direction of traflic flow in the individual lane, provides for the automatic directing or channeling of the vehicle detection impulse to a counting or measuring device according to the direction of travel of the vehicle so actuating the vehicle detector.

From another aspect the present invention provides a novel lane changing system for control of the directional flow of trafiic in two or more traffic lanes of a multi-lane roadway in which each of two or more trafiic lanes is individually controlled by a master lane changer thus providing one master lane changer for each lane of the two or more traflic lanes with each of the master lane changers partly controlled by the other master lane changer and partly controlled in common by one comparison device or master controller to allocate certain of such lanes to selected directions during normal or substantially balanced trafiic conditions as well as during certain unbalanced traflic conditions so as to provide positive allocation of directional use of the controlled trafiic lanes at all times except during transition from one directional allocation to another directional allocation.-

With the present novel system employed for individual control of directional allocation of each lane of two adjacent traflic lanes located between additional trafiic lanes, use of the two adjacent traffic lanes may be allocated to opposite directions of traffic flow respectively during normal or substantially balanced traflic with use of both lanes allocated to the same directional trafiic flow during peak trafiic conditions. Such system and apparatus may include partial control of one master lane changer by the other master lane changer so as. to in sure that the desired cycle of allocation of the reversible lane is obtained.

OBIEGTS OF INVENTION It is an object of the present invention to present an improved system or apparatus for the control of the direction of traffic flow in a lane or lanes by reversing the direction of traffic flow in certain of the lanes of a multi-lane roadway or the like automatically, through traffic actuation, by the traffic traversing the controlled roadway, received from a sampling point or points along the roadway over a timedv period, with means for allocating use of the certain lane or lanes to one directional traffic tfow during at least a minimum period while rohibiting the opposite directional traffic flow from the certain lane or lanes, followed by a timed clearance period during which the traffic flow having last been allocated use of the certain lane or lanes is cleared or warned to leave such lane or lanes while still prohibiting the opposite traffic flow from thecontrolled lane, and thereafter prohibiting both trafiic flows from the certain lane or lanes or providing a cautionary indication therein for at least a minimum period before permitting allocation of the certain lane or lanes exclusively by either traflic flow.

Another object is to present an improved actuated system and apparatus for the control of the directional flow of trafiic on certain of the lanes. of a multi-lane roadway that has such degree of flexibility that. a certain directional phase of trafiic flow may, after having terminated, be repeated before providing the opposite directional phase of traffic flow, according. to the demand of the traffic along the controlled roadway.

A further object is to present an improved actuated controlled system for controlling the direction of traffic fiow along a lane or lanes of a multi-lane roadway serving bi-directional trafiic having at least a minimum period prohibiting vehicles in the lane or lanes following a clearance period of such lane or lanes between two directional periods.

A still further object is to provide an improved system and apparatus for controlling the direction of traflic flow along a lane or lanes of a multi-lane roadway serving bi-directional tratfic and having a control cycle including one part of the cycle for directional allocation of the lane or lanes which one part of the cycle is common to both directional allocations alternatively, as presented for one direction or the other.

Another object is to provide a novel system and apparatus for the control of directional traffic in at least two adjacent interior traffic lanes of a multi-lane roadway by individually controlling the direction of traffic flow in each individual lane of the two adjacent interior tratfie lanes by the use of lane changers individual to each lane, with the lane changers interconnected so as to provide partial control of each lane changer by the other with both lane changers controlled in common by a comparison unit or master controller.

It is still another object to provide an improved lane changing system in which positive allocation of a lane or lanes of a multi-lane roadway serving bi-directional traffic may be made at all times except during transition from one allocation of direction to another allocation of direction.

A still further object is to provide an improved lane changing or reversing system in which two or more lane changers are employed to control a similar number of lanes of a multi-lane roadway with the lane changers individually favoring one direction of traffic flow so that during peak traffic both lane changers will allocate their respective lane to the same direction of traffic flow and during average or non-peak trafiic periods each lane changer will allocate its respective lane or lanes to the opposite directional trafiic flow from the other.

T ralfic measuring and comparison aspects- 0 reversible lcme system It is already known to provide apparatus for selection, by traffic actuation at a suitable trafiic sampling point, between different types or lengths of trafiic control cycles for a traffic signal system or to adjust the time of the overall traflic signal system st ep-by-step at short time intervals to accommodate the actual traffic variations as they occur, Such apparatus may be employed in the present system to select a step in a scale of steps which step is proportional to the volume of trafiic actuating such apparatus.

Apparatus of this character is sometimes referred to as a cycle selector and is disclosed in US. Patent Number 2,288,601, issued July 7, 1942, to John L. Barker.

In the preferred embodiment of the present invention, allocation of use of a lane or lanes of a multi-lane roadway, to one directional flow of traffic is made in accordance with the relative position of selected steps oftwo comparable scales, each scale beingv divided into comparable steps with one of the steps of each scale selected by a cycle selector in response to vehicle actuation of traffic in one directional flow. One scale may represent inbound trafiic, for example, and the other scale may represent outbound trafiic, for example and the individual steps of the scale may represent progressive measure.- ments of the trafiic flow or traffic volume, for example. The relation between the selected steps of two comparable scales may be determined by a system selector which may be in the form disclosed in the aforesaid U.S. Patent 2,542,978, issued February 27, 1951, to John L. Barker.

Accordingly one cycle selector and its associated vehicle detector units are provided to detect and measure. inbound vehicle trafilc at an appropriate sampling point on a multi-lane roadway serving bidirectional traflic of which one or more traffic lanes are to be used as reversible. lane or lanes to accommodate the predominately heavy trafiic flow while another cycle selector and its associated vehicle detector units are provided to detect and measure outbound vehicle trailic at an appropriate sampling point on the same roadway. The terms inbound and outbound are representative and used merely for convenience of' identifying opposite directions of traffic flows.

The steps of the scale or cycle positions selected by each cycle selector may correspond to the volume or measurement of trafiic detected in each respective direction on the roadway and selection is made in the form of energizing an output line selected among several output lines. The several output lines of the steps of the respective scales are applied to a system selector which may be referred to as a master controller and the master controller determines the relation between the energized steps of the respective scales and accordingly sets up a demand for certain traffic conditions. Response to such demand is made by a master lane changer which may proceed through a cycle of operations and provide outputs for control of one or more local lane changes or signal control circuits which provide the desired signal indications over the trailic lane or lanes of the controlled roadway.

The position and number of sampling points along a roadway are a matter to be determined by the length of the controlled reversible lane or lanes and the character and pattern of the trafiic. It may be desired to have multiple sampling points for each directional trafiic flow along a controlled highway that is relatively long so that the differential between two directional flows of trafiic along the roadway will more faithfully represent the differential between the two directional flows along the entire roadway rather than at the sampling point only.

If the controlled roadway is relatively short and is a roadway with numerous access roads along its length it may be desired to have sampling points for each traffic flow more or less centrally located along the length of the roadway.

If, on the other hand, the controlled roadway is relatively short and/or is without access roads along its length, for example, a tunnel or bridge, efiective sampling points may be placed at each end of the tunnel or bridge to sample the approaching traffic or entering traffic from each direction.

Reversible lane control systems of FIG. 1 and FIG. 6 and in general For purposes of illustration of the invention relative to FIGS. 1 and 6 it will be assumed that the controlled roadway is a three lane road accommodating two way trafiic, for example, inbound and outbound. The northbound lane, for example, may be for trafhc inbound to a business area of a city and the southbound traffic lane, for example, may be for trafirc outbound away from the business area. During normal traflic conditions, one lane, L1, the easterly lane of the roadway will be used by inbound trafiic, and one lane, L3, the westerly lane of the roadway will be used for outbound traffic. The center lane, L2, during normal traflic conditions will be used as a butter lane or safety zone between the inbound and outbound traiiic.

In the field of traffic control it is known that at various times large increases of traffic flow in one direction occurs, as for example in the morning, people may travel into the city to their place of employment, and in the afternoon, people may travel from the city to their homes.

This increase in trafiic flow in one direction is generally referred to as peak tratiic and peak tralfic periods will occur at different times of day according to the season, weather, public events that attract numerous people and according to the days of the week, for example, weekdays and weekends.

The invention as embodied in block form in FIG. 1 and FIG. 6 automatically provides exclusive use of additional travel space or trafiic lanes for peak traffic as determined from a relation between measurements of the two traffic flows of the tratrlc itself. During non-peak traffic periods or balanced traffic periods such additional traffic space or lane is employed either as a buffer zone between two traffic flows or as a lane used by both traffic flows for passing only, when safe.

It will be assumed that the center lane of a roadway will be controlled so that during periods of peak traffic flow use of the center lane will be permitted by such peak traffic flow. Thus, during peak inbound traffic periods (inbound to a city, for example) the inbound traflic will be permitted to occupy the center lane as well as the easterly lane L1 which is here considered the normal lane for inbound trafiic, while outbound traflic is restricted to the westerly lane, L3 its normal lane. During peak outbound trafiic periods (outbound from a city, for example) the outbound traflic will be permitted to occupy the center lane as well as the westerly lane L3 while inbound trafiic is restricted to the easterly lane L1. During non-peak or normal, or average traflic flow periods the center lane will be employed as a safety or buffer zone between the two traffic flows.

According to one form of the invention, the trafiic actuated detector units, of which there would be two accorded to inbound trafiic and two accorded to outbound trafiic, would be so placed that one detector would be actuated by inbound traflic in the easterly lane L1 and one detector would be actuated by outbound trafiic in the westerly lane L3. The two remaining detector units, one for inbound traffic and the other for outbound traffic, would be placed so as to be actuated by trafiic using the center lane L2 of the roadway. One such detector would be associated with, and in close proximity to the inbound trafiic detector in the easterly lane and the remaining, or fourth detector would be associated with and in close proximity to the outbound traffic detector in the westerly lane of the roadway.

The detector units may be of any of the well known type of detectors in general use for vehicle trafiic actuation. They may be either pressure operated, magnetic or sound sensitive, electrical or electronic, or may be of the radar type. These detectors may be directional or nondirectional under diiferent circumstances as pointed out more fully below.

In some cases, as will be later explained, one such detector unit, of the two detector units placed in the center lane, may be omitted so that three detector units may be used instead of four. In the case of multiple sampling points a number of detector units in excess of three or four, as the case may he, would be used depending upon the number of sampling points along the roadway. If three detector units were to be used at one sampling point, as will be later explained more completely, a single detector in the center lane would serve both inbound and outbound trafiic. The detector unit, being common to each directional traffic flow, may be a bidirectional detector in one case or a non-directional detector in another case as fully explained herein below.

In the operation of the cycle selector apparatus from its broader aspects, the inbound and the outbound streams of traflic are respectively measured or counted over a period of time and during such time period the individual cycle selectors remain in a given cycle position of a scale of such positions corresponding to a scale of trafiic volumes previously measured.

Near the end of such traffic sampling time period, the individual cycle selectors determine whether to remain on the cycle position or to change to another and different position, in accordance with the trafiic count, for example. If the trafiic counted in one direction is substantially the same as in the preceding sampling time period the cycle selector associated with that direction remains on the same cycle position but if that trafiic flow has increased substantially, the cycle selection associated with that trafiic fiow will select the next higher cycle in the series unless the cycle selector is then selecting the highest cycle in such case it will remain on the highest cycle, or if the traflic count in one direction has decreased substantially, the cycle selector associated with that direction of traffic flow will select the next lower cycle in the series unless the cycle selector is then on the lowest cycle position and then it will remain on the lowest cycle position.

At the end of each sampling time period, the counting of traffic is reset and another sampling period is started. Each cycle selector has a number of different steps or cycle positions from which to select. US. Patent No. 2,288,601, referred to, illustrates six steps or cycle positions, from A to F, for example, although it is obvious that more or less could be provided if desired. The

operation and complete description of the cycle selector is disclosed in the said Patent 2,288,601.

The operation of the system selector provides a means of setting up a demand in the lane changing system that will control allocation of use of the center lane of a roadway between the inbound traffic flow and the outbound traffic flow in accordance with the relative positions of the inbound and outbound cycle selectors. If, for example, the inbound and outbound cycle selectors are both on the same or corresponding steps or cycle positions, or not more than one cycle position apart, the system selector in accordance with one aspect of operation, will set up a demand in the lane changing system for a signal sequence which would deny use of the center lane to both inbound and outbound traffic and maintain the center lane of the roadway as a butler lane or safety zone between the two directional trafiic flows.

When the inbound and outbound cycle selectors are two or more cycle positions apart indicating a substantial difierence in traffic volume or measurement in the respective directions, the system selector will select the highest cycle position and set up a demand to allocate use of the center lane to the trafiic flow associated with the cycle selector then selecting the higher cycle position, thus according two lanes to one directional traffic flow as against one lane for the use of the other directional trafiic flow.

When during a subsequent sampling time period the inbound and outbound cycle selectors return to corresponding cycle positions or are not more than one cycle position apart, the system selector will set up a demand in the lane changing system for a signal sequence that will convey instructions to traflic in the center lane to vacate the center lane to the right and will then prohibit use of the center lane to all vehicles and thereby maintain the center lane as a butter lane or safety zone between the inbound and outbound traflic flow.

The signals used to control traffic in the center lane may be the conventional green for go, or use yellow for caution, or vacate or clearance, and red for stop or do not use. The use of arrows in the conventional color or signs conveying instructions may be desired to indicate non-use and to instruct the vehicle operators to vacate the lane by driving to the right.

Generally, the location of the signals controlling the use of the center lane may be overhead, in the center of the lane and placed between intersections, so as to eliminate possible confusion with the signals controlling intersection trafiic. However, signals at intersections might supplement or coordinate in the lane allocation. The signals may very well be in a series of two sets of three signals back to back so to speak, one set of green, yellow and red signals that would be visible to and controlling inbound traffic and the second set visible to and controlling outbound trafiic. The signals may be a set of double faced signals, that is, one unitcontaining three signals on each of two opposite faces and visible to and controlling the respective opposite directional trafiic fiows, the signals themselves being individually controlled.

It is preferred that the distance between signals controlling the directional traffic flow may be such that the inbound motorist, for example, can look ahead and see at least two sets of signals that control the inbound trafiic fiow and the outbound motorist, for example, can look ahead and see at least two sets of signals, at one time, that control the outbound trafiic flow.

SUMMARY OF DRAWINGS FIG. 1 illustrates, in block diagram form, a traflic actuated lane changing system employing apparatus according to one embodiment of the invention.

FIG. 2 illustrates, in circuit diagram form, a preferred form of the master lane changer with a cam chart associated with the cam contacts illustrated in the diagram, at the bottom of the figure.

FIG. 3 illustrates, in circuit diagram form, a preferred embodiment of the local lane controller usable in the systems of FIGS. 1 and 9 for example.

FIG. 4 illustrates, in circuit diagram form, a preferred form of the detector selector utilizing two single detector units for detection of trafiic in the center lane, for use in FIG. 1 for example.

FIG. 5 illustrates, in circuit diagram form, an alternate form of detector selector utilizing a single detector unit for detection of trafiic in the center lane for use in the several systems.

FIG. 6 illustrates in block form an alternate traffic actuated lane changing system employing apparatus differing somewhat from the apparatus employed in FIG. 1.

FIG. 7 illustrates a circuit arrangement combining the master lane changer, shown in FIG. 2 with the local lane changer shown in FIG. 3.

FIG. 8 illustrates, in circuit diagram form, the selfselecting detector selector employing a single bidirectional detector unit for traffic detection in the center lane for use in FIG. 1 or FIG. 6, for example.

FIG. 9 represents in block diagram form another alternate form of traffic actuated lane changing system employing apparatus for individual control of two revers ible lanes.

FIG. 10 illustrates, in circuit diagram form an alternate form of lane changing unit or master lane changer.

General aspects of reversible lane system of FIG. 1

Referring now to FIG. 1 in more detail a section of roadway RY of a three lane road, formed by two solid lines, is illustrated extending from left to right along the upper part of the figure. The two broken lines, within the two solid lines, separate the roadway into three lanes, L1, L2 and L3. This roadway section illustrated may be part of a street, highway, or thoroughfare, for example, through which extends a controlled reversible center lane.

On the roadway, in sets of two, are four traflic actuated detector units, ID and IDD, that would detect inbound trafiic and OD and ODD that would detect outbound traflic. These detector units may be of any well-known type adapted to close a pair of contacts upon passage of a vehicle, for example.

The detector unit ID, in the inbound lane L1, actuated by inbound trafiic, is linked electrically to the cycle selector ICS which cycle selector will measure or count the inbound vehicle traffic in lane L1 during the sampling time periods. The detector OD, in outbound lane, L3, actuated by outbound trafiic, is linked electrically to the cycle selector OCS, which cycle selector will measure or count the outbound vehicle trafiic in lane L3 during the sampling time periods.

The detector unit IDD, in center lane L2 is associated with detector unit ID and is connected to the detector selector DS. During those periods that the inbound traffic is granted use of center lane, L2, detector selector DS, as will be fully explained hereinafter, links detector unit IDD electrically to cycle selector ICS through line IDL. The detector unit ODD in center lane L2 is associated with detector unit OD and is also conntcted to detector selector DS. During those periods that the out bound traflic is granted use of center lane, L2, detector selector DS links the detector unit ODD electrically to cycle selector OCS through line ODL.

Detector selector DS is connected electrically to the master lane changer MLC through lines GI and GO.

Cycle selector, ICS, associated with inbound traflic, is connected to system selector MC by six lines AI, B1, C1, DI, EI and F1, which represent a separate circuit connection for each of the six cycle positions of cycle selector ICS. Likewise cycle selectOr, OCS, associated with outbound traffic, is connected to system selector MC by six lines A0, B0, C0, D0, EO and F0, which are 9 Separate connections for each of the six cycle positions of cycle selector OCS.

System selector MC is connected to master lane changer MLC by two lines IG and G, the use of which will be explained in detail hereinafter. Master lane changer MLC and local lane changer LLC are connected electrically by three lines, MIG, MOG and MCL. It is to be understood that one local lane changer is shown here for convenience of explanation, however, there could be multiple local lane changers spaced, as desired, along the controlled highway. The local lane changers would be conected in parallel to the master lane changer via the three lines MIG, MOG, and MCL with a common return through a ground line.

Local lane changer LLC is connected to the signals that control traffic on the controlled highway. The signals IGS, IYS, and IRS, green, yellow and red respectively, for inbound trafiic control and 068, OYS, and CR5, green, yellow and red respectively, for outbound trafiic control are shown as two sets of three signals each for convenience. It is to be understood that the signals may be ot any variety of colored light signals or mechanical device such as a movable arm or a semaphore type signal, for example. The light signals may be in the form of arrows or flashing signal lights or signs with lettered instructions.

Master lane changer 0 FIG. 2 and relation to FIG. 1

FIG. 2 herein illustrates a circuit diagram of the master lane changer, shown in the block diagram of FIG. 1 as a rectangle lettered MLC. The circuit of the master lane changer appears in FIG. 2 with a cam chart below the circuit diagram.

The circuit is arranged for 120-volt alternating current with the positive or ungrounded power terminal indicated by a plus in a circle in the upper left and the negative or grounded power terminal indicated by a minus in a circle in the upper right. The negative power line on the right marked 10, will be considered to be a common ground line. Lines IG and OG are input lines from the system selector shown in FIG. 1 as a rectangle lettered MC. Line IG continued through switch 211 and junction 211, is the input line for relay IR and line OG continued through switch Ztltl and junction 201 is the input line for relay OR. Relay IR is connected to ground line by lines 11 and 1t), and relay OR is connected to ground line 10 by lines 12 and 16. Relay IL is connccted to the AC. input line 15 through a series of contacts that are controlled by relays IR,- OR, CL and G as will be hereinafter described in detail. Relay IL is connected to ground line 10 by lines 16 and 10. Relay OL is connected to the A.C. input line 15 through several contacts that are controlled by relay IR, OR, CL and G, as will be described in detail hereinafter. Relay OL is connected to ground line 10 by lines 17 and 1%.

Relay CL is connected to AC. input line 15 through line 18, cam contacts C1-C2, when closed, and line 19. The cirsuit is completed to ground line 11) through lines 20 and 10. Relay G is connected to the AC. input line 15 through line 18, cam contacts D1-D2, when closed, and line 21. The circuit for relay G is completed to ground line 10 through lines 22 and 10'.

Relays IGR and OGR are connected to the AC. input line 15 through a series of contacts controlled by relays IL, 0L and G, as will be explained hereinafter. Relay OGR is connected to ground line 10 by lines 23 and 24 and relay IGR is connected to ground line 10 by line 24.

A motor ST, used for timing purposes, controls the cam contacts A1-A2, A2-A3, Bit-B2, B2-B3, C1-C2, D1-D2, E1-E2 and E2-E3 which cam contacts are opened and closed in a predetermined sequence as will ill results, as for example a familiar telephone rotary stepping switch or line switch rotated by a motor magnet controlled by a timing device.

The motor ST is connected to the AC. input line 15 through a series of contacts that are controlled by relays OR, 0L, IR, and IL, and the cam contacts A1-A2, A2- A3, B1-B2, and B2-B3. The circuit from motor ST is completed through line 25 to ground line 10. The circuit of the master lane changer is presented in a rest position corresponding to position R1 on the cam chart below with relays IR, OR and CL energized and with the contacts controlled by the corresponding relays up. Cam contacts A2-A3, B2-B3, C1-C2 and E1-E2 are closed. Switch 200 is presented closed, in contact with point 201 and switch 216 is presented closed, in contact with point 211.

Relay OR, illustrated energized, controls contacts 31, 32, 33/34, 34/35 and 214. Relay OL, illustrated deenergized, controls contacts 36, 37, 38/39, 39/41 41, 42/43 and 43/44. Relay IR illustrated energized, controls contacts 45, 50, 51, 52 and 204. Relay IL, illustrated deenergized, controls contacts 53, 54/ 55, 55/56, 57, 58/59 and 52/60. Relay G, illustrated deenergized, controls contacts 61, 62 and 63. Relay CL, illustrated energized, controls contacts 64 and 65. Relay OGR illustrated deenergized, controls contacts 70 and 71 while relay IGR shown deenergized, controls contacts 72 and '73.

Lines MIG, MOG, and MCL are output lines of the master lane changer. Lines GI and GO, associated with lines MIG and MOG respectively are also output lines of the master lane changer.

As seen in FIG. 1 the lines MIG, MOG and MCL connect the master lane changer electrically with the local lane changer and lines GI and GOconnect the master lane changer electrically with the detector selector.

In FIG. 1 the local lane changer is illustrated in block form as a rectangle lettered LLC while the detector selector is illustrated in block form as a rectangle lettered DS.

The broken line H1 which appears across FIG. 2 and FIG. 7 shall be explained below.

Below the circuit diagram illustrated as FIG. 2 is a cam chart which indicates the relative opening and closing positions of the several cam contacts with relation to the time of one complete revolution of the cam shaft.

The length of time of one revolution depends upon the type of thoroughfare controlled, the distance between signals, the method of clearance to be employed, the amount of clearance time desired and the length of time of the minimum green period desired.

The space between the vertical lines forming the left side and the right side of the cam chart represents an amount of time equal to one complete rotation of the cam shaft. On the left side are the letters and numbers A1-A2, A2-A3, 131-132, BIZ-B3, C1-C2, Dl-DZ, E1-E2 and 152-153 which represent the eight (8) pairs ofam contacts associated with the cam shaft. The same letters and numbers are used to identify the cam contacts as are used in the circuit drawing as seen in FIG. 2 above, for convenience of identification.

The horizontal line to the right of each letter and number representing a pair of cam contacts represents the amount of time, relative to the time of one cycle, that the pair of cam contacts are closed and at what relative position in the cycle such closure is made. The short vertical line on the horizontal lines are used to emphasize the beginning and the end of the period of closure. Where no horizontal line appears during any part of the cycle, it is an indication that such cam contact is open.

The shaded vertical areas R1 and R2 indicate the two rest positions of the cam shaft. R1 indicates a rest or stop period when the signal lights will show red in both directions on the reversible lane, according to the descrip tion offered herein. R2 indicates a rest or stop period when the use of the reversible lane will be accorded to one directional flo'w of traflic, as determined by the system and apparatus.

On the lower left the words Signal Sequence" refer to the line to the right of the words. The horizontal line is separated into shorter segments by short vertical lines. The short segments represent periods of time, relative to the complete cycle time of the cam shaft, that the several combinations of signal lights will be shown. G/ R indicates a green signal showing in one direction and a red signal showing in the opposite direction. During this phase the use of the reversible lane will be granted to one directional traflic flow, the other directional flow being denied use of the reversible lane.

Y/ R indicates a yellow signal showing in one direction and a red signal showing in the opposite direction. During this phase the yellow signal will be shown to the traflic that had last been granted use of the reversible lane while the red signal will remain illuminated against the other directional traflic flow. This phase may be called a clearance phase since this would be the time in the cycle employed to clear the reversible lane for the next phase. R/ R indicates the all-red phase when a red signal is showing to each directional traflic flow thereby keeping all traflic ofl the reversible lane.

The period 6/ R may be the inbound phase or the outbound phase as determined by which directional trafiic flow is granted use of the reversible lane.

Signal control circuit diagram of FIG. 3

FIG. 3 herein illustrates a circuit diagram of a signal control circuit which may be represented in block form .as rectangle LLC in FIG. 1. FIG. 3 may also serve as a signal control circuit that may be associated with FIG. 10.

The lines MIG, MOG and MCL represent input alternating current power lines and may represent the lines similarly labeled extending from the block MLC in FIG. 1 or may represent the lines similarly labeled and represented as extending from the circuit diagram in FIG. 10. The lines MIG, MOG and MCL may supply power for relays IGL, OGL and GY respectively. Line MIG may supply power to relay IGL, the circuit being completed via lead 81 and 80 to the common ground 100. Line MOG may supply power to relay OGL the circuit being completed via leads 82 and 80 to ground 100. The line MCL may supply power to relay GY the circuit being completed via lead 83 and 80 to ground 191).

The relays IGL and OGL are illustrated deenergized and the relay GY is illustrated energized. This condition of the relays IGL, OGL and GY may be the normal condition of the relays and circuitry of FIG. 3 when associated with the master lane changer of FIG. 2 with the master lane changer in its rest position R1, as illustrated in FIG. 2 herein.

The relay IGL in FIG. 3 controls contacts 161/102, 102/103, 104/105 and 105/106. The relay OGL in FIG. 3 controls contacts 111/112, 112/113, 114/115 and 115/116. Relay GY in FIG. 3 controls contacts 121/122, 122/123, 124/125 and 125/126.

The use of switches SW1 and SW2 will be described below.

The broken line boxes FL1 and FL2 represent circuit interrupters or flashers that may provide flashing signals and are in one of the circuits for the yellow signals. The use of these flashers will be explained below.

The inbound signal lamps IGS, IYS and IRS, green (G), yellow (Y) and red (R) respectively may be illuminated by the l20-volt alternating current represented by a plus in a circle. Circuits are completed from the input line 110 to ground line 1% through the several contacts controlled by the relays IGL, OGL and GY, and the various signal lamps to illuminate one of the inbound signal lights, as explained hereinafter.

The outbound signal lamps OGS, OYS and ORS may be similarly illuminated through separate circuits, as explained below.

The signal lamps IGS, IYS and IRS may represent the inbound signal lamps that are represented in FIG. 1 and identically labeled, extending from the left side of block LLC.

The signal lamps OGS, OYS and ORS may represent the outbound signal lamps that are represented in FIG. 1 and identically labeled, extending from the right side of block LLC.

Generally, when only relay IGL is energized as by energization of lead MIG, a circut is completed to illuminated signal lamp IYS while a second circuit illuminates signal lamp ORS. The combination of relays IGL and GY energized, as by energization of leads MIG and MCL, complete circuits to illuminate signal lamps IGS and ORS. When only relay OGL is energized as by energization of lead MOG signal lamps IRS and OYS are illuminated. The combination of relays OGL and GY energized, as by energization of leads MOG and MCL, cause illumination of signal lamps IRS and OGS.

When relay GY is alone energized, as by energization of lead MCL, as illustrated in FIG. 3, or when relays IGL and OGL are both energized with relay GY deenergized, or when all three relays are deenergized the signal lamps IRS and ORS are illuminated, when the switches SW1 and SW2 are positioned as illustrated.

Comparison 0] lane changers of FIG. 2 and FIG. 10

It should be noted that although during normal traflic condition periods the lane changing unit of FIG. 2 keeps its output leads MIG and MOG deenergized, as will be more clearly described below, the alternate form of lane changing unit, illustrated in FIG. 10 maintains both leads MIG and MOG energized during comparable periods. Thus both lane changer units, although providing opposite outputs under similar traffic conditions, may cause to provide similar signal display to tralfic on the roadway.

With switch SW1 and switch SW2 in contact with junction 107 and junction 108 respectively and the relays IGL and OGL both energized, as in the normal traflic condition of the alternate lane changing unit, FIG. 10, circuits may be completed to illuminate signal lamps IYS Via switch SW1, junction 107 and flasher FL1 while signal OYS is illuminated via switch SW2, junction 108 and flasher FLZ.

This arrangement of the switches SW1 and SW2 of FIG. 3 may provide flashing yellow signals to both inbound and outbound traflic during normal traific conditions.

The flashing yellow signals may indicate to tratfic that the reversible lane may be used by both inbound and outbound traffic for passing only, when safe.

It may be desirable to provide a flashing yellow signal at any time the yellow signal is illuminated. This may be accomplished by moving the flasher so that its electrical location is adjacent to the yellow lamp. The combina tion of relays OGL and GY when energized cause the illumination of signals IRS and OGS. When relay GY is alone energized as illustrated in FIG. 3, or all three relays are energized or all three relays are deenergized the signals IRS and ORS are illuminated.

Detector selector circuit diagram of FIG. 4

FIG. 4 is a circuit diagram of the detector selector. At the top of the figure, illustrated as a pair of open contacts, are two vehicle actuated detector devices IDD and ODD, for example. These two detector units are comparable to the two detector units, as seen in FIG. 1, in center lane L2 of the roadway RY labeled IDD and ODD. The detector selector is also illustrated in block form labeled DS in FIG. 1. Lines IDL and ODL of FIG. 4 are comparable to the similarly labeled lines in FIG. 1. The lines GI and GO of FIG. 4 are also seen in FIG. 1 identically labeled.

The relay RDI controls contact D51 and relay RDO controls contact D52. Line GI supplies an A.C. input 13 to relay RDI and the circuit is completed through lines 131 and 131 to a common ground line 130 while line GO supplies an AC. input to relay RDO which circuit is completed through line 131 to ground line 130.

Line IDL supplies an input from the detector selector DS to the inbound cycle selector ICS, as shown in FIG. 1, the circuit from ground 130 is completed through lines 132 to 132, detector unit IDD, contact DS1 to line IDL. Line ODL supplies an input from the detector selector DS to the outbound cycle selector OCS, as shown in FIG. 1, the circuit from ground 130 is completed through line 132', detector unit ODD, contact DS2 to line ODL.

Detector switching circuit diagram of FIG.

FIG. 5 is a circuit diagram of a detector switching unit arranged for use with a single detector CD. The two detector circuits are controlled by the relays SDI and SDO, which relays control contacts in the two detector circuits. Power is supplied from line IDL to contact D811, when closed, to contact DS12/DS13, when closed to the detector CD. The detector circuit is complete through line 165 to a common ground line 166. The other detector circuit is powered by an input through line ODL to contact DS13/DS14, when closed to detector CD and is completed through line 165 to the common ground line 166. Relay SDI is energized by input power through line GI and the circuit is completed through lines 168 to 167 to ground line 166. Relay SDO is energized by input power through line GO and the circuit is complete through line 167 to ground line 166.

The circuit in FIG. 5 is presented with both relays deenergized and both detector circuits open.

Alternate form of lane changing system of FIG. 6

FIG. 6 represents in form another lane changing system differing somewhat from the lane changing system of FIG. 1.

For reasons of convenience and simplification those units in FIG. 1 and in FIG. 6 that are identical are identified with the same numbers and/0r letters in both figures.

Referring to FIG. 6 in more detail, a roadway RY is illustrated by two solid horizontal lines across the top of the figure. The roadway RY is separated into three lanes L1, L2 and L3 by two broken lines inside the two solid lines. The roadway section illustrated may be part of a street, highway or thoroughfare for example through which extends a reversible center lane.

On the roadway are three traffic actuated detector units; ID represents a detector in lane L1 that would detect inbound traific in lane L1 and OD represents a detector in lane L3 that would detect outbound trafi'ic in lane L3. BD illustrates a bi-directional detector that is set in lane L2 and is used to detect both inbound and outbound traffic when either inbound or outbound trafiic has been granted use of the center lane.

The detector units ID and OD could be either directional or non-directional type vehicle detectors.

The detector unit ID in the inbound trafiic lane L1, actuated by inbound traffic, is connected to the cycle selector ICS, which cycle selector will measure or count inbound vehicle trafiic in lane L1 during traflic sampling time periods. Detector ID and cycle selector ICS of FIG. 6 are comparable to detector ID and cycle selector ICS as seen in FIG. 1 and are similarly labeled for convenience.

Detector OD, in the outbound traffic lane L3, actuated by outbound vehicle traffic, is connected to the cycle selector OCS, which cycle selector will measure or count outbound vehicle traffic in lane L3 during trafiic sampling time periods. Detector OD and cycle selector OCS of FIG. 6 are comparable to detector OD and cycle selector OCS as seen in FIG. 1 and are similarly labeled for convenience.

Detector unit BD, located in lane L2, represents a bidirectional detector that may be actuated by inbound or outbound trafiic, in center lane L2. The detector ED is connected to the self-selecting detector selector BDS. The self-selecting detector selector is connected to the cycle selector ICS by line IDL and to the cycle selector OCS by line ODL. The cycle selector ICS is connected to the system selector MC by six lines AI, BI, CI, DI, EI and F1 while the cycle selector OCS is connected to the system selector MC by six lines A0, B0, C0, D0, EO and F0. The system selector MC is connected to the lane changer LC by two lines 16 and 0G. These lines, as will be completely explained hereinafter, supply the input for certain relays in the lane changer. To the left of the lane changer LC is illustrated a group of three signal lights IGS, IYS and IRS. These signal lights represent a group of lights that control inbound trafiic in the reversible lane. On the right of the lane changer is a similar group of signal lights OGS, OYS and ORS that represent signal lights that would control outbound trafiic in the center or reversible lane. Both groups of signal lights in FIG. 6 are similar to the similarly labeled signal lights in FIG. 1.

The letters inside the signals represent R for red, Y for yellow and G for green.

The general description of FIG. 7 will be omitted at this time but will be presented later in the specification.

Self-selecting detector selector circuit diagram 0 FIG. 8

FIG. 8 is a circuit diagram of the self selecting detector selector that is represented in block form in FIG. 6 and labeled BDS. Through the use of a bi-directional pres sure sensitive vehicle detector and the circuitry illustrated, the direction in which a vehicle is traveling as it passes over and actuates the bi-directional detector may be employed to determine to which cycle selector, ICS or OCS, the detection impulse is to be channeled.

At the top of FIG. 8 is one type of bi-directional vehicle detector unit BD, represented by a cross section view of the bi-directional detector with a common base plate GP and two upper contact plates PI and PO. Relays IDR and ODR are energized from an A.C. input, represented by a plus in a circle, through line 170. The completion of the relay circuit depends upon the position of the contacts above the relay. The circuit is completed through these contacts to the plates of the detector, depending upon which contact plate either P1 or PO is first closed by pressure, to the ground plate GP to line 171 to ground line 175. The lines IDL and ODL, which lines may be similar to the identically labeled lines in FIG. 6 are input lines to the cycle selectors ICS and OCS respectively and the circuit is completed to ground line 175, which is here considered to be a common ground, through contact D523 and lines 173 and 174 for line ODL and contact D827 and line 174 for line IDL,

The relay ODR controls contacts DS20/DS21, DS21/ DS22 and D823 while relay IDR controls contacts DS24/DS25, DS25/DS26 and D527.

Lane changing system with plural interlinked individually reversible interior lanesF1G. 9

FIG. 9 represents in block diagram form another alternate form of lane changing system in which two adjacent interior lanes of a multi-lane roadway serving bidirectional tratfic, may be individually controlled so that the reversible lanes are positively allocated to one direction of traffic, or the other direction of trafiic except during transition of one or both reversible lanes.

Individual control over each lane of two adjacent interior reversible lanes, L22 and L33 is obtained through use of two master lane changers MLCl and MLC2, each partially controlled by the other master lane change and both controlled in common by a system selector or master controller MC.

By adjustment of certain switches, as more fully described below, during average or balanced traffic conditions the lane L22 will be allocated to one direction of trafi'ic and the lane L33 will be allocated to the other di- 15 rection of traflic so that, for example, lanes L11 and L22 will be allocated to inbound traflic and lanes L33 and L44 will be allocated to outbound traffic.

During outbound peak traffic conditions lanes L22, L33 and L44 will be allocated to outbound traffic while lane L11 remains allocated to inbound traflic and during inbound peak trafiic conditions lanes L11, L22 and L33 will be allocated to inbound traffic while lane L44 remains allocated to outbound traffic.

Each master lane changer may individually control a detector selector that is associated with the reversible lane over which that master lane changer exerts control.

Alternate form of master lane changer FIG.

FIG. 10 is a schematic circuit diagram of an alternate form of master lane changer or lane changing unit that may be employed in a lane changing system, as illustrated in FIG. 1 for example, with FIG. 10 illustrating circuitry that may be found in the block MLC.

As more fully described below, the lane changing unit of FIG. 10 is illustrated as being controlled via leads IG and 0G which lead may be outputs of a master controller, such as block MC in FIG. 1, for example.

Output leads of the lane changing unit may be the leads MIG, MOG and MCL or other outputs as described below that may extend to a signal control circuit, as for example block LLC, in FIG. 1.

Description 0] system of FIGS. 1, 2 and 3 in various assumed conditions Referring more fully to the block diagram of FIG. 1, a multi-lane roadway RY, including lanes L1, L2 and L3 is illustrated at the top of the diagram representing a roadway of three or more trafiic lanes serving bi-directional traffic Lane L1 may be permanently allocated to inbound vehicle trafiic and lane L3 may be permanently allocated to outbound vehicle trafiic. Lane L2 may, during average or balanced traflic periods, be kept vacant of vehicle traffic and thus may serve as a buffer or safety zone between inbound traflic and outbound traffic, or may be allocated to both directions of trafiie flow as a passing lane only, as desired. During peak traffic periods, use of lane L2 will be accorded to the peak trafiic flow whether it be inbound or outbound traffic.

The signal lights that control the directional traflic flow will be assumed to be overhead signals, over the center of each individual lane. The signals over the center of lane L1 will show green for inbound trafiic and red for outbound traffic as this lane will always be accorded to inbound traflic and, for purposes of explanation, never accorded to outbound traflic. The signal light over the center of lane L3 will show green for outbound traffic and red for inbound trafiic as lane L3 will always be accorded to outbound traffic and never to inbound traffic. It may be desired to use descriptive signs over lanes L1 and L3 or to leave the lanes unsignalized and unidentified, as desired.

It should be understood that although lanes L1 and L3 are illustrated as one lane each they may each be two lanes or more each, according to the width of the roadway controlled. The signal lights over lanes L1 and L3 may very well be a single double-faced signal light showing green in one direction and red in the other direction. These signals will not change for purposes of this explanation.

Lane L2, the center lane, will have sets of three signals visible to each directional flow of traffic. These signals will be the set IGS, inbound green signal, IYS, inbound yellow signal, and IRS, inbound red signal, located overhead, in the center of the lane position and visible to inbound trafiic. The set of signals OGS, outbound green signal, OYS, outbound yellow signal, and ORS, outbound red signal, will be located overhead in the center of the lane position visible to outbound traffic. The two sets of signals will be placed, for description purposes, back to back, overhead in the center of lane L2 at a site along the highway RY between two intersections so as to eliminate possible confusion with intersection control signals.

The vehicle actuated detector unit may be placed at any point or points along the highway. However, for purposes of illustration, it will be assumed that the detectors will be centrally located along the length of the highway. The detector ID, used to detect inbound traffic in lane L1, and the detector IDD, used to detect inbound trafiic in lane L2, will be placed in the respective lanes and in a line perpendicular to the longitudinal line of the highway RY similar to the illustration in FIG. 1. The detector OD, used to detect outbound traflic in lane L3, and the detector ODD, used to detect outbound trafiic in lane L2 will be placed in the respective lanes also in a line perpendicular to the longitudinal line of the highway RY as illustrated in FIG. 1. The inbound detectors ID and IDD, and the outbound detectors OD and ODD may be placed in close proximity to each other.

The physical location of the detector selector DS, the two cycle selectors ICS and OCS, the system selector, MC and the master lane changer may be any convenient place. They may be placed in close proximity to the highway RY or away from the highway whichever may be desired. The local lane changer LLC may also be located with the above mentioned equipment or located at the side of the highway RY in close proximity to the signal lights.

Assuming master lane changer at rest in position R] with red signals in both directions in reversible center lane In the following description it will be originally assumed that the master lane changer MLC is at rest in position R1, as presented in FIG. 2, with power applied to the output line MCL to the local lane changer LLC.

The signal lights, over center lane L2 of roadway RY, as controlled by the local lane changer, will show red signals illuminated to both inbound traffic and outbound trafiic so that use of center lane L2 is denied to both inbound and outbound traffic.

According to the present assumed conditions the as sumed system maintains center lane L2 as a buffer lane or safety Zone, during average or non-peak trafiic conditions, between the inbound and outbound traffic flows.

With all traflic restricted from the center lane there will be no actuations on either detector IDD or ODD.

However, the inbound traffic in lane L1 will be crossing over detector ID causing actuation of the detector ID and the outbound traflic in lane L3 will be crossing over detector OD causing actu-ations of the detector OD.

The detector ID is connected to the cycle selector ICS from where the detector ID receives its power, while the detector OD is connect-ed to the cycle selector OCS from where the detector OD receives its power.

FIG. 1 and FIG. 6 are illustrated in single line, block form and although no specific source of power or ground connection is illustrated it should be understood that local power is applied to the individual units of the system as illustrated in the individual circuit diagrams and that ground returns complete the circuit where neces sary.

The cycle selectors ICS and OCS, as more fully described in Patent No. 2,288,601, are arranged for op eration with an input supply of l20-volt alternating current. An output lead supplies current to the respective detector with the circuit completed through the detector and returned through a common ground line. The cycle selectors may be arranged for two or more detectors each, in such case the detectors IDD and ODD would be connected to the respective cycle selector via separate circuits, as illustrated in FIG. 1. If the cycle selectors were arranged for one detector, an additional detector, the detector IDD for example, may be connected in parallel with detect-or ID to the cycle selector ICS via line IDL to the circuit of detector ID and the detector ODD for example, may be connected in parallel with 17 detector OD to the cycle selector OCS via line ODL to the circuit of detector OD.

Instead of each cycle selector incorporating a separate timer for setting up the traflic sampling periods as in Patent No. 2,288,601 previously mentioned, for purposes of the present invention it is preferable to employ a common timer to time the traffic sampling time period for both of the cycle selectors ICS and OSC as has been fully explained in Patent No. 2,542,978 heretofore mentioned.

In FIG. 1 herein each of the cycle selectors ICS and OCS have been illustrated as having six cycle position output lines AI, BI, CI, DI, EI, and F1 for cycle selector ICS and A0, B0, C0, D0, EO, and F for cycle selecetor OCS. These six output lines correspond to the six cycle positions A, B, C, D, E, and F of the Patent No. 2,288.601 referred to. In the present embodiment the output lines of each cycle selector, six lines for each, are individually connected to separate terminals in the system selector MC, having twelve terminals in all.

Each of the cycle selectors connects AC. power to one of its output circuit terminals which corresponds to the cycle position it is then selecting, and maintains power on this output terminal until another output terminal is selected at the end of one of the subsequent traffic sampling time periods.

As is more fully explained in Patent No. 2,542,978, the inbound cycle selector ICS will apply electric power on one of its cycle position output circuits of its AI to F1 cycle scale in accordance with the cycle it is selecting at the moment in response to its measurement of trafiic actuating the trafiic detector ID. Correspondingly cycle selector OCS will apply power on one of its six cycle position circuits of its A0 to PO cycle scale in accordance with the cycle it is selecting in response to its measurement of trafiic actuating the detector OD. Thus these circuits from the cycle selectors provide input control circuits to the system selector MC and accordingly the system selector provides power on its appropriate output circuits IG and 0G to provide selection of the appropriate input power to the master lane changer MLC.

The output circuits IG and 0G, as seen in FIG. 1 illustrated as extending from the bottom of the system selector MC, represent circuits which are individually energized to provide power to certain relays, IR and OR, in the master lane changer MLC, as seen in FIG. 2.

As will be more fully described hereinafter, this arrangement permits the choice of four different cycle control combinations by these two circuits IG and 0G. With power on line 16 only, relay IR will be energized while relay OR remains deenergized and with power on line 06 only, relay OR will be energized while relay IR remains deenergized. The third combination would be the case of power on both lines IG and 0G to energize both relays IR and OR while the fourth combination would deene-rgize IG and OG thereby keeping both relays IR and OR deenergized.

Assuming approximately equal trafiic inbound and outbound with master lone changer at rest in position R1 Assuming the master lane changer to be at rest as heretofore stated, let it be assumed that the trafiic flow in both directions along the roadway RY illustrated in FIG. 1, is light and that the number of vehicles traveling in either direction is approximately equal. Referring in particular to FIG. 1, let it also be assumed that the detectors ID and OD have been detecting the presence of vehicles so that the corresponding cycle selectors have both selected a cycle. Thus cycle selector ICS is main taining powers to the system selector MC via line BI for example and cycle selector OCS is maintaining power to the system selectorMC via line BO for example during the present traffic sampling time period. Let it be further assumed that the cycle selector-s are now sampling the present respective trafiic flows.

With the cycle selectors having both selected similar cycle positions, BI and B0, the system selector maintains both the output lines 16 and 0G energized, which lines maintain both relay IR and OR energized. Referring to FIG. 2 with relay IR and OR energized and the master lane changer MLC at rest in position R1 as shown on the cam shaft chart, relay CL is energized via a circuit that may be traced from the AC. input 15 through line 18, closed cam contacts C1C2, line 19 to the coil of relay CL, line 20, line 111' to ground line 10. Relay IR is energized from the system selector MC through line IG, switch 210, point 211, point 216, the coil of relay IR to lines 11 and 1% to ground line 10. Relay OR is energized from the system selector MC through line OG, switch 2%, point 201, point 206, the coil of relay OR to lines 12 and 11) to ground line 10. With both relays IR and OR energized, relays IL and OL are deenergized since contact 32 of relay OR, which has been opened by energized relay OR, breaks the energizing circuit for relay IL and contact 45 of relay IR, opened by energized relay IR, breaks the energizing circuit for relay OL. Relay G is deenergized since the cam contacts D1-D2, in its energizing circuit, are open. The timing motor ST is stopped since both contact 57, of relay IL, and contact 41, of relay OL, are open and fail to complete a circuit to the AC. input at line 15 to energize the timing motor ST.

With relays OL and IL deenergized, relays OGR and IGR are also deenergized.

Relay CL, now energized, closes its contact 65 which contact completes the output circuit MCL of the master lane changer to AC. input 15. The output lines MIG and MOG of the master lane changer have no power applied to them since both relays OGR and IGR are deenergized and certain of their respective contacts are open to maintain lines MIG and MOG deenergized.

Output lines MIG, MOG, and MCL of the master lane changer supply power to the relays IGL, OGL, and GY, respectively, of the local lane changer as seen in FIG. 3.

Following the system through it is found that the relay GY, seen in FIG. 3, is energized from the output power of the master lane changer via line MCL through the coil of relay GY, lines 83 and to ground line 100.

Relay GY closes its contacts 121/122 and 124/125 and opens its contacts 122/123 and 125/126.

With relays IGL and OGL both deenergized AC. power from input line 110 flows through the line 84 to contacts 102/103 of relay IGL to line 85 to the red signal IRS to ground thereby illuminating the red signal IRS to inbound trafiic indicating that inbound traflic shall not use center lane L2. AC. input power is also applied through the lines 110, and 86, contacts /116 of relay OGL to line 87 to the red signal ORS to ground 100 thereby illuminating the red signal ORS to outbound trafiic indicating that outbound trafiic shall not use center lane L2 thereby maintaining center lane L2 as a butter zone between the two flows of directional trafiic.

It should be noted that the signals IGS, inbound green, IY S, inbound yellow, IRS, inbound red, OGS, outbound green, OYS, outbound yellow and ORS, outbound red are externally located in the system but are illustrated in FIG. 3 as interior elements for convenience of illustration.

Since there is no power on output lines MIG and MOG of the master lane changer in FIG. 2, there is also no power in output lines GI and G0. The output lines GI and GO supply no power to the detector selector DS, illustrated in FIG. 4, so that both relays RDI and RDO are deenergized thereby keeping the detectors IDD and ODD in center lane L2 without power which when applied would be applied via lines IDL and ODL from the cycle selectors through contacts of relays RDI and RDO to each detector respectively.

Operation of master lane changer from rest position R1 to rest in position RZ-assuming zrafiic change from approximately equal inbound-outbound to heavier inbound Let it be assumed that trafiic conditions along the controlled highway remain relatively constant and both inbound and outbound trafiic are restricted to lanes L1 and L3 respectively. After an appreciable time inbound trafiic traveling in lane L1 increases so that at the end of a subsequent trafiic sampling period cycle selector ICS decides to change positions and selects the next higher cycle position CI for example, while cycle selector OCS still selects the same cycle position BO for example, since outbound traflic remains relatively constant.

Assuming that the system selector will react only when there is a difference of two or more cycle positions between the cycle selectors, tralfic remains restricted from lane L2.

Increased inbound traffic counted during the following trafiic sampling time period causes cycle selector ICS to select a still higher cycle position so that now for example the line DI is energized by cycle selector ICS while cycle selector OCS still energizes line B0.

The two cycle selectors would now be two cycle positions apart energizing non-corresponding input terminals in their respective bank of input terminals to the system selector MC. The system selector MC would deenergize the output line G and cause relay OR, in the master lane changer MLC, seen in FIG. 2, to become deenergized while the output line IG remains energized keeping relay IR in the master lane changer energized.

Relay OR closes its contact 32 causing relay IL to be energized via a circuit from the A.C. input line 15 through line 74, contact 61 of G relay, contact 64 of CL relay, line 66, Contact 32 of OR relay, contact 50 of IR relay, line 67, the coil of IL relay, line 16, line to ground line 10.

With IL relay energized, contact 57 of IL relay would close and complete a circuit to energize the motor ST through a circuit from A.C. input line 15, line 68, contact 57 of IL relay, line 69, cam contacts BZ-B3, cam contacts A2-A3 the motor ST, line 25 to ground line 10. The motor ST would advance the cam shaft in its cycle, out of the rest position R1, open its cam contacts B2- B3 and close its cam contact B1B2 to maintain power from A.C. input line through line 18 to point 18', earn contacts Bl-BZ, cam contact A2-A3 through the coil of the motor ST, line 25 to ground line 10 to keep the motor running, thus advancing the cam shaft in its cycle.

Relay IL would close its contact 53 to prepare a lock-in circuit to keep itself energized.

The cam shaft would be advanced by the motor ST and close cam contacts D1-D2, thus completing the energizing circuit for relay G from the A.C. input line 15, through line 1 8, cam contacts D1'D2, line 21, the coil of relay G, line 22, line 10 to ground line 10.

The relay G would close its contact 62, which contact is known by those skilled in the art as a make-beforebreak contact composed of contacts 61 and 62, thereby completing the lock-in circuit for relay IL from the A.C. input line 15, line 74, contact 62 of G relay, contact 53, line 67 to the coil of relay IL, line 16, line 10' to ground line 10.

The relay IL, when energized, closes its contacts 58/ 59 to prepare a circuit to energize relay IGR. With relay G energized, its contact 63 is closed to complete the circuit to energize relay IGR from the A.C. input line 15 through line 6-8, contact 63 of relay G, line 75, contact 43/44 of relay O-L, contact 58/59 of relay IL, the coil of relay IGR, line 24 to the ground line 10.

Relay IGR opens its contact 72 to insure that the output line MOG is not energized and closes its contact 73 completing a circuit from A.C. input line 15, through line 76, contact 71 of relay OGR, contact 73 of relay IGR to energize the output line MIG. The output line MCL is energized from the A.C. input through line 15, contact 65 of relay CL to line MCL.

Now both output lines MCL and MIG are energized with output line MOG deenergized.

Referring now to FIG. 3 both relays IGL and GY would now be energized. Relay IGL is energized via the energized input line MIG through the coil of the relay IGL, line 81 to line to the ground line while relay GY remains energized from the energized input line MCL as previously explained.

The relay IGL would close its contact 1111/1112 and complete a circuit from A.C. input line through line 84, contact 101/102 of relay IGL, contact 11 2/ 113 of relay OGL, contact 121/122 of relay GY to green signal 165 to ground line 160 thereby illuminating the green inbound signal while the red outbound signal remains illuminated through a circuit from the A.C. input 110 through line 86, contact /116 of relay OGL, line 87, signal ORS to ground line 100.

With output line MIG in the master lane changer energized, the output line G1 is also energized through a circuit, as seen in FIG. 2, from the A.C. input via lines 15 and 76, contact 71, contact 73 to line GI. As seen in FIG. 4, the circuit diagram of the detector selector, also illustrated in FIG. 1 as a rectangle designated DS, the output line GI of the master lane changer is the input line supplying AC. power to the relay RDI through its coil to line 13 1, line 13 1' to ground line 130. The input line GO, supplying power to relay RDO of the detector selector, would be deenergized so that relay RDO would be deenergized.

Relay RDI would close its contact DS1 to complete the input power line from the inbound cycle selector ICS through line IDL, contact DS1 of relay RDI to detector IDD, in center lane L2, the circuit being completed through lines 13 2, 13 2 to ground line 130.

With power applied to the detector IDD, the inbound traffic traveling in center lane L2, now receiving a green signal, would actuate the detector IDD and the actuations would be received by the inbound cycle selector, ICS, so that an accurate sampling of the inbound trafiic flow is received by the inbound cycle selector. The detector ODD also in center lane L2 would not have power applied to it so that it would not be elfective at this time.

The motor ST, in FIG. 2, continues to advance the cam shaft in its cycle until the cam contacts A2-A3 open and A1A2 close. When cam contacts A2-A3 open and A11A2 close, the energizing circuit for the motor ST opens and the motor ST stops in the rest position, R2, as indicated on the cam chart below the circuit diagram in FIG. 2. The A.C. power from line '15, through line 18 to contact 54/55 of relay IL would be broken by open contact 52 of relay IR to stop the motor ST while the signals remain green for inbound trafiic in lane L2 thereby granting inbound traflic use of center lane L2, as well as lane L1, while outbound traffic is restricted to lane L3 by a red signal showing for outbound traffic over lane L2.

So long as inbound cycle selector ICS selected a cycle of two or more positions higher than the position selected by out-bound cycle selector OCS at the end of subsequent traffic sampling periods, the lane changing system will remain in the position in which it is now assumed. It should be understood that the system selector may be adjusted to respond to a difference of one position between the cycle selectors or more than one position. Here it has been assumed that the system selector shall respond initially to a difference of two or more positions between the cycle selectors.

During the traffic sampling time periods with the lane changing system in the presently assumed position, inbound cycle selector ICS is receiving actuations from two detectors, ID and IDD, both actuated by inbound traffic while outbound cycle selector OCS is receiving actuations from one detector OD, actuated by outbound trafiic.

21 Operation of master lone changer from rest in position R2 to position Rlassnming decrease in inbound trafiic from heavier inbound to approximalely equal inbound and outbound Let it be assumed that the numerically superior inbound trafiic decreases while the number of outbound vehicles remains approximately as previously assumed so that again the amount of inbound vehicles traveling over the highway RY and the amount of outbound vehicles traveling over the highway are, for purposes of explanation, approximately balanced numerically.

The decrease in the volume of inbound trafiic over the lanes L1 and L2. would become apparent to inbound cycle selector ICS through reduced actuations of detectors ID, in lane L1, and TDD, in lane L2, while the relatively constant volume of outbound traffic in lane L3 would be apparent to outbound cycle selector OCS through actuations of detector OD, in lane L3.

The volumes of the opposing traffic flows would be reflected in the cycle positions selected by the respective cycle selector at the end of a traflic sampling time period.

The resulting change of relative cycle positions will cause system selector MC to energize both output lines 16 and G. Energization of both lines IG and GO cause the master lane changer MLC to start the motor ST and thereafter deenergize its output lines MlG, MOG, GI and GO. Signal changes are accomplished and upon deenergization of lines MIG and MOG, both red signals are illuminated. Upon deenergization of both lines GI and GO both detectors IDD and ODD are removed from the counting circuits of the associated cycle selectors.

The sequence of change to restrict trafiic from the center lane begins by extinguishing the green inbound signal IGS and illuminating the yellow or clearance inbound signal IYS for trafiic in lane L2 while the red outbound signal ORS remains illuminated. Yellow signal IYS will remain illuminated for a predetermined time, as set by adjustment of the cams on the cam shaft in the master lane changer. At termination of the clearance period the yellow signal will be extinguished and the red inbound signal IRS will be illuminated.

Thus with both red signals IRS and ORS illuminated to the trathc flow each controls the cam shaft will reach its rest position R1 and remain at rest until a change in relative cycle positions is accomplished at the end of a subsequent trafiic sampling time period.

At the end of a traffic sampling time period, during which time the reduced actuations were received, the inbound cycle selector ICS determines a cycle position in accordance with the volume of inbound traffic flow in lanes L1 and L2. The outbound cycle selector OCS determines a cycle position in accordance with the volume of outbound traffic flow in lane L3. It has been assumed that the both traffic flows are approximately balanced so that the cycle position BI and B0 for example would be selected by the respective cycle selectors.

The output circuits represented by BI and B0 from the respective cycle selectors ICS and OCS would be energized to deliver power to the comparable input terminals in the system selector MC. The system selector MC maintains power on its output line 1G and restores power to its output line 0G.

During the preceding period, as previously described, relays CL, G, IL and IR of the master lane changer MLC, FIG. 2 had been energized. With power from the system selector MC now applied to its output line OG, relay OR is energized as previously described. Contact 33/34 of relay OR is closed to complete an energizing circuit for motor ST, from A.C. input line 15, line 18, point 18, contact 51 of relay IR, contact 33/34 of relay OR to line S8 to cam contact A1-A2 to the coil of the motor ST, through line 25 to ground line 10.

The motor ST advances the cam shaft in its cycle out of the rest position R2 and cam contacts A1-A2 open as cam contacts A2-A3 close. The green inbound signal and the red outbound signal hold traffic until the cam shaft is rotated to open cam contacts C1-C2, the relative position of the cam action may be observed from the cam chart below the circuit diagram in FIG. 2. The opening of cam contact C1-C2 breaks the energizing circuit for relay CL. Deenergized relay CL releases its contact 65 which opens and deenergizes output line MCL of the master lane changer so that now only output line MIG is energized. With line MCL deenergized, the relay GY in FIG. 3 becomes deenergized and the signals in lane L2 change from green inbound to yellow inbound while the outbound signal remains red. The circuit in FIG. 3 to illuminate yellow inbound signal IYS may be traced from the AC. input through line 84, contact 101/102 of relay IGL, contact 112/113 of relay OGL, contact 122/123 of relay GY, signal IYS to ground line 100.

The yellow inbound signal and the red outbound signal on lane L2 would remain illuminated until the motor ST rotates the cam shaft so that cam contacts DI-DZ, as seen in the cam chart in FIG. 2, open. When cam contacts Dl-DZ open, the energizing circuit for relay G is broken and relay G releases its contact 62 and breaks the energizing circuit for relay IL.

Deenergized relay IL releases its contact 57 to prepare to deenergize the motor ST when the cam contacts BI-BZ opens and B2-B3 closes.

Contact 63 of relay G is released opening the energizing circuit for relay IGR. Deenergized relay IGR releases its contact 73 to deenergize the output lines MIG and GI.

When the output line MIG becomes deenergized, power to energize relay IGL of FIG. 3 is interrupted and relay IGL becomes deenergized. Relay IGL closes its contact 102/103 causing red signal IRS for inbound traffic on lane L2 to be illuminated. The yellow inbound signal on lane L2 is extinguished by opening contact 101/192.

Signal ORS is maintained illuminated through a circuit previously described and thus both inbound and outbound traffic are restricted from the lane L2.

The cam shaft in FIG. 2. continues to be rotated by motor ST and cam contacts C1-C2 close. The energizing circuit for relay CL is completed, as previously described and energized relay CL closes its contact 65 to apply power to output line MCL.

Although the lane changer MLC energizes relay GY, in FIG. 3, there is no change in the signals displayed on lane L2 at this time.

As output lines MIG and GI become dcenergized, relay RDI of the detector selector, FIG. 4, becomes deenergized. Relay RDI releases its contact D51 and breaks the detector circuit for detector IDD from the output line IDL, from the cycle selector ICS, so that any actuations on detector IDD would no longer affect the inbound cycle selector ICS. The rotation of the cam shaft continues until cam contacts B1-B2 opens and BIL-B3 closes thereby breaking the energizing circuit for motor ST at its rest position R1.

The master lane changer will remain in its rest position, R1, so long as both input lines IG and 0G remain energized. The system selector MC Will maintain the lines TG and 0G energized so long as inbound cycle selector ICS and outbound selector OCS select cycle positions that are not more than one position apart, the cycle positions selected depending upon the number of actuations received by the individual cycle selectors from the associated detector during a traffic sampling time period.

Attention is now directed to the cam chart in the lower part of FIG. 2. The length of time necessary to complete one cycle may vary according to the speed of rotation of the motor used to rotate the cam shaft. The preferred time is from six (6) to ten (10) minutes for one complete rotation. The time of one cycle and the setting of the cams determine the minimum time for each signal period.

Referring in particular to the line Signal Sequence, it may be observed that the cam shaft may rest with red signals illuminated to both inbound and outbound traffic,

at R1 or may rest in R2 and show a green signal to one traffic fiow and a red signal to the other. If the cam shaft should come to rest at either R1 or R2, or both, during the course of one cycle such resting would substantially lengthen the time of one cycle by the period in which the cam shaft came to rest. This rest period is determined by relative trafiice conditions along the roadway.

The clearance period, during which period a yellow signal is illuminated to one trafiic flow and a red signal to the other, does not include a rest position so that the time of the clearance period will remain set, as desired.

The above description disclosed the method and operation resulting in the use of the center lane being accorded to inbound traflic, outbound traffic being restricted therefrom, the clearing of the inbound trailic from the center lane, followed by the restriction of both inbound and outbound trathc from the center lane L2 according to the actuations of the inbound traffic and the outbound trafiic individually.

It is necessary to note that should the trafiic again be unbalanced in favor of the inbound trafiic, the operation of the lane changing system would repeat that which was described above, to accord use of center lane, L2, to the inbound trafiic,

Operation of master lane changer from rest in position R1 to rest in position R2'assuming outbound traflic becomes heavier However, let it now be assumed that the volume of inbound trafiic remains approximately the same and the volume of outbound traffic along the highway RY increases.

As the outbound traflic volume increases, there would be additional actuations on the outbound detector OD accordingly, while the actuations on the inbound detector ID would remain constant, due to the constant volume of inbound traffic along the highway as assumed.

The increased outboundtraflic actuatio-ns Would be refiected in outbound cycle selector OCS and, at the end of a subsequent traflic sampling time period in which the increased outbound trafiic actuations were received by outbound cycle selector OCS, outbound cycle selector OCS would advance to a higher position in the cycle, for example DO, while the inbound cycle selector ICS, which had received approximately the same Volume of actuations during successive sampling periods from its detector ID, due to a constant volume of inbound traffic, would remain on the same cycle position, for example, BI.

The cycle positions selected by the cycle selectors would cause the system selector, MC, to maintain output line OG energized and deenergize output line IG resulting in certain internal reactions in the master lane changer MLC, hereinafter described, to change the signals over the lane L2 so that use of center lane L2 would be granted to outbound traflic signified by a green signal to outbound trafiic over center lane L2 and use of center lane L2 denied to inbound trafiic, signified by a red signal to inbound trafiic over center lane L2.

The output power through circuits BI and DO from the cycle selectors ICS and OCS respectively would be applied as input power to the system selector MC.

Energized output line OG, from the system selector, would maintain power to energize the relay OR in the master lane changer MLC, in FIG. 2, while deenergized output line IG would cause the relay IR, in the master lane changer MLC to drop out.

Relay IR would close its contact 45 to energize relay OL from the A.C. input line 15, through line 74, contact 61 of relay G, contact 64 of relay CL, line 66, contact 45 of relay IR, line 89, contact 31 of relay OR, the coil of relay OL, line 17, line to ground line 10.

Relay 0L would close its contact 41 to energize the motor ST through a circuit from the A.C. input line 15, line 63, line 68', contact 41 of relay 0L, line 69', line 69 to cam contacts B2B3, cam contact A2-A3 to the coil of the motor ST, line 25 to ground line 10.

The motor ST being thus energized would revolve the cam shaft and open cam contacts B2-B3 and close cam contacts Bit-B2 to complete a circuit from the A.C. input line 15, through line 18, terminal 18, earn contacts B1- B2, cam contacts A2A3 to the coil of'the motor ST, line 25 to ground line 10.

Relay OL would close its contact 42/43 to prepare an energizing circuit for relay OGR.

As the cam shaft continues to revolve, the cam contact Dl-DZ would close to complete an energizing circuit for relay G as previously described. Relay G would close its contact 62 to complete an energizing circuit to keep relay 0L energized from the A.C. input line 15 through line 74, contact 62 of relay G, line 90, contact 36 of relay OL, the coil of relay OL, line 17, line 10' to ground line 10.

Relay G would close its contact 63 to complete the prepared circuit from the A.C. input 15, line 68, contact 63 of relay G, line 75, line contact 59/60 of relay IL, contact 42/43 of relay OL, the coil of relay OGR to line 23, line 24 to ground line 10, thereby energizing relay OGR.

Relay OGR would close its contact 70 to energize output lines MOG and GO from the A.C. input line 15, through line 76, contact 72 of relay IGR, contact 70 of relay OGR to the output lines MOG and GO.

Now both output lines MCL and MOG to local lane changer LLC would be energized.

Relay OGL in FIG. 3 is energized from the output power line MOG from the master lane changer through the coil of relay OGL, line 82 to line to ground while relay GY is energized by the output power line MCL, the coil of relay GY, line 83 to ground 100. The energizing of both relays OGL and GY would cause an outbound green signal to be illuminated over center lane L2 through a circuit from the A.C. input line 110, through line 86, contact 114/115 of relay OGL, contact /106 of relay IGL, line 91, contact 124/125 of relay GY, signal OGS to ground line 100.

The red inbound signal over center lane L2 would remain illuminated through the circuit from the A.C. input line 110, line 84, contact 102/103 of relay IGL, line 85, signal IRS to ground line 100. The outbound red signal ORS is extinguished by the opening of contacts /116 of relay OGL.

Output power line GO, from the master lane changer MLC, would energize relay RDO of the detector selector, FIG. 4, through the coil of relay RDO, line 131' to ground line 130. Relay RDO would close its contact DS2 to apply power for the detector circuit from the outbound cycle selector OCS through line ODL, the contact BS2 of relay RDO, detector ODD, line 132' to ground line 130. This completion of the detector circuit to detector ODD in lane L2 would cause the outbound vehicles traveling in lane L2 to be counted by the outbound cycle selector OCS during the trafiic sampling time periods when such outbound trafiic crosses the detector ODD thereby affording means of obtaining an accurate sampling count of the outbound traflic in both the lanes L2 and L3.

The motor ST in FIG. 2 Would advance the cam shaft in its cycle until the cam contacts A2-A3 open and A1 A2 close thus changing the energizing circuit of the motor ST. The energizing circuit would now be broken by contact 39/40 of relay OL which contact would now be open. The motor ST would stop in its rest position R2.

Operation on sudden Ira fie change from heavier outbound t0 heavier inbound There may be occasions when opposing trafiic will change greatly with respect to each other, for example, let it now be assumed that the outbound traffic, which heretofore was just considered to be numerically superior to the inbound traffic along the highway, suddenly decreases appreciably while the inbound tratfic increases 25 and becomes numerically superior to the outbound trafiic.

Let it be further assumed that this substantial change in the relationship between inbound and outbound traffic results in the cycle selectors reversing their cycle positions so that inbound cycle selector ICS advances from position BI to DI and outbound cycle selector OCS drops from position D to B0, for example.

It should be noted that in the previous descriptions and assumptions a change of such amplitude was not considered.

Such a change in trafiic conditions along the controlled highway would require a complete reversal of center lane L2 from use of the center lane L2 by outbound trafiic to use of the center lane L2 by inbound traffic. This reversal is accomplished by a change of signals so that the outbound traffic signals in center lane L2 are changed from a green outbound signal to a yellow outbound signal while the inbound tratfic signals remain red. The combination of inbound red and outbound yellow would be followed by a minimum period during which a red signal is displayed to both inbound and outbound traffic. After such minimum period a green inbound traffic signal would be illuminated, the red inbound signal being extinguished, while the red outbound traffic signal remains illuminated, thereby granting use of center lane L2 to inbound trafi'ic.

The reduced volume of outbound vehicle trafiic and the increased volume of inbound trafiic is reflected, from the detector ID, in lane L1, being actuated by inbound trathc, and the detectors OD in lane L3, and ODD in lane L2, being actuated by outbound traflic and in the selected cycle positions of the respective cycle selectors ICS and OCS. The cycle selectors ICS and OCS would apply power through lines DI and B0 respectively to the system selector, MC, which would in turn energize its output line IG and deenergize its output line OG.

Relay OR, in the master lane changer MLC, in FIG. 2, would be deenergizcd and relay 1R in the master lane changer MLC, would be energized through a circuit previously described.

When relay OR becomes deenergized, it releases and closes its contact 34/ 35 thereby completing an energizing circuit for the motor ST from the AC. input through line 18, terminal 18', contact 37 of relay OL, contact 34/ 35 of relay OR, line 88, cam contacts A1-A2, the coil of motor ST, line 25 to ground line 10. Energized motor ST starts rotating the cam shaft, the cam shaft moves out of its rest position, R2, and opens its cam contacts A1- A2 and closes its cam contacts A2-A3 to complete another circuit for motor ST through cam contacts A2A3 and B1B2 as previously described.

The cam shaft continues to rotate while the green outbound signal and the red inbound signal over center lane L2 hold until cam contacts C1-C2 open to cause relay CL to become deenergized.

Deenergized relay CL releases and opens its contact 65 to deenergize output line MCL.

Deenergizing output line MCL is reflected in the local lane changer LLC, as seen in FIG. 3, by deenergization of relay GY. When relay GY is deenergized, it opens its contact 124/125 and closes its contact 125/126. This extinguishes the outbound green signal over center lane L2 and illuminates a yellow signal for outbound traffic in lane L2 through a circuit from the AC. input line 111), line 86, contact 114/115 of relay OGL, contact 105/106 of relay IGL, line 91, contact 125/ 126 of relay GY, signal OYS to ground line 100. The red inbound trafiic signal over center lane L2 remains illuminated as previously described,

The outbound yellow signal over center lane L2 remains illuminated until the cam shaft advances and opens the cam contacts D1D2.

The opening of cam contacts D1-D2 cause deenergization of relay G. Contacts 62 and 63 of relay G are opened causing deenergization of relays O1 and OGR respectively. Deenergized relay OGR opens its contact 70 which contact causes output lines MOG and GO to become deenergized.

With output lines MIG, MOG and MCL, from the master lane changer MLC, deenergized, the relays IGL, OGL, and BY in the local lane changer, FIG. 3, are deenergized so that the outbound yellow signal would be extinguished and the outbound red and inbound red signals would both be illuminated over center lane L2. Signal ORS is illuminated via a circuit from the AC. input 110, through line 86, contact 116 of relay OGL, line 87, signal ORS to ground 100. Signal IRS is illuminated via a circuit from the AC. input 119, through line 84 contact 192/103 of relay IGL, line 85, signal IRS to ground 1011.

With output line GO deenergized, the relay RDO in the detector selector DS, FIG. 4, is deenergized. Contact D52 of relay RDO is opened to break the detector circuit between line ODL and detector ODD in lane L2. At this point the outbound vehicle traffic is counted by actuations on the detector OD in lane L3 and the inbound traffic is counted by actuations on the detector ID in lane L1. Detectors IDD and ODD in lane L2 are both disconnected and unused.

The inbound red signal and the outbound red signal over the center lane L2 would remain illuminated for a minimum period determined by the setting of the cams on the cam shaft.

The motor ST in FIG. 2 would advance the cam shaft in its cycle and the cam contacts C1C2 would close thereby completing the energizing circuit for relay CL. Relay CL would close its contact 64 thus completing an energizing circuit for relay IL from the AC. input 15 through line 74, contact 61 of relay G, contact 64 of relay CL, line 66, contact 32 of relay 0R, contact 50 of relay IR to the coil of relay IL, line 16, line 10' to ground line 10.

The relay IL would close its contact 57 to prepare an energizing circuit for motor ST when, in due course of its cycle, the cam shaft would be rotated to open cam contact B1-B2 and close cam contacts B2-B3. With contact 57 of relay IL closed, an energizing circuit as previously described, would maintain power to energize motor ST through a circuit as previously described so that rotation of the cam shaft would not be halted in its rest postion R1 but would continue in its cycle, pass through the rest position R1, open the cam contacts B2 B3 and close cam contacts B1 and B2.

As heretofore described, rotation of the cam shaft would close cam contacts D1D2 to complete the energizing circuit for relay G through a circuit from A0 in put line 15, through line 18, cam contacts Dl-DZ, line 511), the coil of relay G, line 22, line 10 to ground line Relay IL would be maintained energized through a lock-in circuit through its own contact 53, as previously explained and, as previously described, relay IGR would be energized.

Identical actions and reactions within the system of the lane changer occur as were previously described with reference to obtaining use of center lane L2 for inbound trailic. The motor ST would continue to rotate the cam shaft until cam contacts AZ-AS open and A1-A2 close at which point motor ST would stop. The stop or rest psition is indicated on the cam shaft chart as position Power would have been applied to the output lines MIG, MCL and GI of the master lane changer MLC, as previously described, with an effect similar to that described above upon the relays of the local lane changer, FIG. 3, and the relay of the detector selector, FIG. 4.

The transition from use of center lane L2 by inbound trafiic to use of center lane L2 by outbound traffic through a substantial change in relationship between inbound and outbound trafiic would be similar to the transition described from outbound traflic use of center lane L2 to inbound traflic use of center lane L2 in that the motor ST would not come to rest in position R1 but would continue revolving the cam shaft to complete one full revolution from rest position R2 through a cycye to again come to rest in position R2.

With use of center lane L2 accorded to inbound trafiic the relays IL and IR would be energized in the master lane changer, FIG. 2, while the relays L and OR would be deenergized.

Detectors ID and IDD actuated by inbound traffic would be included in the counting or sampling of the inbound traffic flow while detector OD would be included in the counting or sampling of the outbound trafiic flow.

To effect a complete transition the relay OR would become energized and relay IR would become clenergized.

With the cam shaft of the master lane changer of FIG. 2 on its rest position R2, deenergized relay IR would close its contacts, including contact 52.

Closure of contact 52 completes a circuit for the A.C. input through lines 15 and 18, contact 54/55, contact 52, line 88, cam contact A1A2, motor ST, line 25 to ground line 10.

The motor ST will advance the cam shaft in its cycle toward position R1, while the signals will change from inbound green to inbound yellow to inbound red, as previously described, while the outbound red signal holds. During the transition when the line GI becomes deenergized the detector IDD is withdrawn from the inbound traffic counting or sampling system. The cam shaft having reached position R1 does not stop but continues toward position R2 to complete the transition. The outbound red signal changes to outbound green while the inbound red signal holds, as fully described above.

When the use of the center lane is accorded to outbound trafiic the detector ODD is included in the counting or sampling system of the outbound traflic, along with detector OD.

If the trafiic flows remain unbalanced in favor of outbound traffic use of the center lane will remain with the outbound traffic flow.

1 It should be noted that should both relays IGL and OGL in FIG. 3 become energized at the same time, for any reason, a circuit is completed to illuminate both inbound red signal IRS and outbound red signal ORS. Si nal IRS is illuminated via a circuit from the A.C. input line 110 through line 84, contact 102/1112, contact 111/ 112, switch SW1, line 85, signal IRS to ground 101 Signal ORS is illuminated via a circuit from the A.C. input line 110 through 86, contact 114/ 115, contact 104/105, switch SW2, line 87, signal ORS to ground 100.

The inbound green or yellow signals and the outbound green or yellow signals would be extinguished by'the opening of contacts 112/ 113 and 105/106 respectively.

Description of detector selector circuit of FIG. 5

FIG. 5 illustrates, in circuit form, another form of detector selector utilizing a single detector CD in lane L2 which would serve as a common detector to count both inbound or outbound traffic in center lane L2 instead of two detectors IDD and ODD in center lane L2, as seen in FIG. 4.

The input lines IDL and ODL from the cycle selectors ICS and OCS are comparable to the similarly lettered input lines in FIG. 4.

The input lines GI and GO as seen in FIG. 5 are comparable to the similarly lettered input lines GI and GO in FIG. 4 and serve similar purposes.

The circuit for input power through IDL or ODL to the detector CD is controlled by the relays SDI and SDO respectively, which relays are energized via the input lines GI and GO respectively.

When input line GI is energized from the master lane changer, during the time the inbound green signal is illuminated, the relay SDI would be energized through a 23 circuit from the input line GI through the coil of relay SDI, line 168, line 167 to ground line 166.

Relay SDI would close its contact D811 to complete a circuit to apply power from input line IDL through contact D811 of relay SDI, contact DS12/DS13 of relay SDO to the detector unit CD to line to ground line 166.

The completion of this detector circuit, with power applied from the inbound cycle selector ICS through the input line IDL, would make the detector CD in center lane L2 part or" the inbound trafiic counting system.

When the input line G1 is deenergized, the inbound trafiic detector circuit would be broken at contact D511 from input line IDL.

When the input line G0 is energized, the relay SDO would be energized through a circuit formed by the input line G0, the coil of relay SDO, line 167 to ground line 166.

Energized relay SDO would close its contact DS13/ D814 and complete a circuit to apply power from the outbound cycle selector OCS through line ODL, contact DS13/DS14 to detector CD to line 165 to ground line 1166.

Completion of the outbound input line ODL to the detector CD in the center lane L2 would make the detector CD part of the outbound trafiic counting system.

With both relays SDI and SDO deenergized, no power is applied to the detector CD so that the detector will not be in either the inbound or the outbound trafiic counting system.

Description of self-selecting detector circuit of FIG. 8

A third method of detecting or counting either inbound or outbound trafiic in center lane L2 is also offered herein. FIG. 8 illustrates a circuit diagram of the self-selecting detector selector which device may be used with a bi-directional detector ED for example. The bidirectional detector BD is illustrated with a common ground plate GP with two contact plates PI and P0. The bi-directional detector ED is also designed that the contact plates PI and PO will make contact with the ground plate GP in sequence, either PI then P0, or PO then PI as a vehicle crosses over the detector, depending on the direction of travel of the vehicle.

When the self-selecting detector selector is used to detect trafiic in center lane L2, for example, a single bidirectional detector of the type illustrated would be placed in center lane L2.

Let it be assumed that use of center lane L2 has been granted to inbound trafilc. The inbound vehicles in the center lane would cross over the hi-directional detector BD so that the plate PI would be compressed to make contact with the ground plate GP and then, rolling the wheels of the vehicle forward, the plate PO would be compressed to make contact with the ground plate GP so that before contact of plate P1 to ground plate GP is broken plate PO would make contact with the ground plate GP.

As contact is made between plate PI and ground plate GP, a circuit would be completed from the A.C. input line 170 through the coil of relay IDR, point 177, line 176, contact DSZtl/DSZI to plate PI, to plate GP, to line 171 to ground line 175 here considered to be a common ground.

Relay IDR thus energized would attract and close its contact DS25/DS26 and D527. The wheel of the vehicle would roll forward and compress plate PO to make contact with the plate GP completing a second circuit before plate PI breaks its contact with plate GP. The second circuit is completed from the A.C. input line 17$ through the coil of relay IDR, point 177, contact DS25/DS26, plate PO to plate GP, line 171 to the ground line 175.

The wheel of the vehicle would roll over and off the plate PI but would still maintain pressure on plate P0. The closure of contact D527 of the relay IDR would com- 21- plete a circuit from the output line IDL from the cycle selector ICS to line 174 to ground line 175.

As the Wheel of the vehicle would pass over and off the bi-directional detector BD, the plate PO would break contact with the ground late GP, breaking the holding circuit for relay IDR which would in turn open its contacts DS25/DS26 and D827.

The action would be obtained each time a wheel of a vehicle crosses the bidirectional detector in that direction so that the plate PI would be first compressed followed by the compression of plate PO.

Assume now that a vehicle crosses the bi-directional detector from the opposite direction for example an outbound vehicle in the center lane L2.

The wheel of the vehicle would first compress plate PO to make contact with the ground plate GP to complete a circuit to energize relay ODR from the A.C. input 171), through the coil of relay ODR, point 179, line 178, contacts DS24/DS25 of relay IDR to plate PO, ground plate GP, line 171 to ground line 175.

Relay ODR would close its contacts DSZ-I/DSZZ and D523. When the wheel of the moving vehicle would compress plate PI to contact the ground plate GP, a circuit would be completed from the A.C. input line 170 through the coil of relay ODR, point 179, contact DS2-1/ D822 to the plate PI, the ground plate GP to line 171 to ground line 175. The circuit through plate PI would be completed before the circuit through plate PO would be broken by the release of the plate PO by the wheel of the vehicle as it crosses the bi-directional detector.

The closure of contact D523 or relay ODR would complete the output circuit from the outbound cycle selector OCS through line ODL, contact D523 of the relay ODR, line 173 to line 174, to ground line 175.

As the wheel of the vehicle would cross over and off the bi-directional detector BD, the plate PI would be released to break the holding circuit for the relay ODR which would then release its contacts DS21/DS22 and D823.

The opening of contact D823 would break the output circuit from the outbound cycle selector OCS through line ODL.

It should be noted that the description above includes overlapping of the contact closures of the plates of the bi-directional detector. If the contact plates are sufliciently far apart so that there would be no overlapping of the contact closures the relays associated with the contact plates, such as ODR and IDR for example, may each be made a delayed action relay with the delay on release. Such delayed action relays would produce the same effect as overlapping contact closures.

Description of alternate form lane changer of FIG. 7

FIG. 7 illustrates, in circuit form, an alternate form of lane changer which is a combination of the master lane change-r, illustrated in FIG. 2 and the local lane changer, illustrated in FIG. 3.

It will be noted that FIG. 2 includes a broken horizontal line H1 across the circuit diagram just below the relay OGR and IGR. FIG. 7 has a similar broken horizontal line H1 across the diagram above the circuits with relays OGR, IGR and CL illustrated in phantom form above broken line H1. The broken line H1 in FIG. 2 and 7 are identical and serve to divide the FIG. 2 and identify such division in FIG. 7.

FIG. 7 shows that part of the circuit of the lane changer that would appear below the broken horizontal line H1 in FIG. 2. The entire circuit of the alternate form of lane changer is not presented in FIG. 7 because that part of the circuit of the lane changer that is not shown in FIG. 7 is identical with the circuit above the broken horizontal line, H1 seen in FIG. 2.

The relays OGR, IGR and CL, illustrated in phantom form in FIG. 7, are identical with the identically lettered relays illustrated in FIG. 2.

The relay CL would control the contacts 157/158, 158/159, 161/162 and 162/163 in FIG. 7 while the relay OGR would control contacts 151/152, 152/ 153, 154/155 and 155/156 in FIG. 7 and relay IGR would control contacts 141/142, 142/143, 144/145 and 145/146 in FIG. 7.

The relays CL, OGR and IGR would be energized through their respective circuits, as appear in FIG. 2, from the A.C. input line 15 similarly numbered with the A.C. input line in FIG. 7.

The signal lights ORS, OYS, OGS, IRS, IYS, and IGS would be illuminated via circuits from the A.C. input 15, through the contact-s as controlled by the relays CL, OGR and IGR to the signals to be illuminated, to common ground line 10.

The signal lights are similar to the signals heretofore described and are used to control directional vehicle travel in center lane L2 as previously described.

The lane changer, as distinguished from the master lane changer, directly controls the signals for control of the center lane L2 Without the necessity of utilizing the local lane changer as illustrated in FIG. 3.

The output lines GO and GI would be energized from points for line GO and 186 for line GI.

Description of lane changing system 0 FIG. 6

Let us assume that an entire lane changing system is composed of the devices as shown in the block diagram. FIG. 6, controlling a roadway RY composed of three lanes, L1, L2 and L3, with center lane L2 the subject of reversible control.

The system disclosed in FIG. 6 utilizes a bi-directional detector BD in lane L2 connected to a self-selecting detector selector BDS illustrated in FIG. 8. This eliminates the necessity of using output lines GI and G0.

The inbound detector ID on lane L1 and outbound detector OD in lane L3, connected to their respective inbound and outbound cycle selectors ICS and OCS, effectively count the inbound traflic in lane L1 and the outbound trafiic in lane L3 during the trafiic sampling time periods. The output circuits of the cycle selectors that are connected to the system selector MC serve identical purposes as previously described.

Inbound and outbound traific in center lane L2 is counted through appropriate actuations of the bidirectional detector BD, as previously explained with reference to FIG. 8, via the output line IDL and ODL of the inbound and outbound cycle selectors.

The output lines 1G and 0G of the system selector MC are energized as previously explained according to the determination of the system selector MC as selected by the relative cycle positions of the cycle selectors.

When there is a relative difference, for example, of two or more cycle positions as selected by the cycle selectors, the system selector will energize and/ or deenergize the appropriate output lines IG or 06, as previously described.

The action within the circuits of the lane changer LC above broken line H1 would be identical to the action of the circuits in FIG. 2 above broken line H1, as previously described. However, where in FIG. 2, the several relays of the master lane changer close contacts to energize output lines to the local lane changer LLC, the lane changer LC, in FIG. 7 closes its own relay contacts to directly illuminate the control signals.

In a manner similar to that previously described, the combination of energizing and deenergizing the relays CL, OGR and IGR would control their respective contacts to illuminate the appropriate signals.

When the relays CL, OGR and IGR are all energized or all deenergized red signals CR8 and IRS are illuminated one signal for each traflic flow thereby denying use of center lane L2. to both inbound and outbound tratfic and maintaining center lane L2 as a butter lane between trafiic in lanes L1 and L3. 

1. A SYSTEM FOR CONTROLLING AND REVERSING THE DIRECTION OF TRAFFIC FLOW ALONG TWO ADJACENT INNER TRAFFIC LANES LOCATED BETWEEN OUTER TRAFFIC LANES ALLOCATED TO OPPOSITE DIRECTIONS RESPECTIVELY ALONG A ROADWAY, MEANS FOR MEASURING TRAFFIC ALONG ALL OF SAID LANES IN THE RESPECTIVE OPPOSITE DIRECTIONS ALONG SAID ROADWAY INDICATING MEANS INDIVIDUAL TO EACH LANE OF SAID ROADWAY FOR INDICATING PERMISSION AND PROHIBITION AND CLEARANCE TO THE POTENTIAL TRAFFIC DIRECTIONS THEREON, COMPARISON MEANS FOR PRODUCING CONTROLLED OUTPUT SIGNALS INDICATIVE OF TRAFFIC MOVEMENT IN ONE DIRECTION EXCEEDING A PREESTABLISHED RELATIONSHIP RELATIVE TO TRAFFIC MOVEMENT IN THE OTHER DIRECTION, MEANS FOR CONTROLLING SAID INDICATING MEANS IN RESPONSE TO SAID CONTROLLED OUTPUT SIGNALS FROM THE COMPARISON MEANS RESULTING FROM SAID TRAFFIC MEASURING MEANS FOR PERMITTING TRAFFIC IN ONE DIRECTION AND PROHIBITING TRAFFIC IN THE OPPOSITE DIRECTION IN SAID TWO ADJACENT TRAFFIC LANES RESPECTIVELY IN RESPONSE TO MEASUREMENT OF SUBSTANTIALLY GREATER TRAFFIC IN SAID ONE DIRECTION THAN IN SAID OPPOSITE DIRECTION IN SAID ROADWEAY AND MEANS FOR CONTROLLING SAID INDICATING MEANS FOR REVERSING THE DIRECTION OF PERMITTED AND PROHIBITED TRAFFIC IN SAID TWO ADJACENT TRAFFIC LANES RESPECTIVELY IN RESPONSE TO SAID COMPARISON MEASUREMENT OF SUBSTANTIALLY GREATER TRAFFIC IN SAID OPPOSITE DIRECTION THAN IN SAID ONE DIRECTION BY SAID MEASURING MEANS, MEANS FOR CONTROLLING SAID INDICATING MEANS IN RESPONSE TO SAID TRAFFIC MEASURING AND COMPARISON MEANS FOR PERMITTING TRAFFIC IN SAID ONE DIRECTION IN ONE LANE OF SAID TWO ADJACENT TRAFFIC LANES AND PROHIBITING TRAFFIC IN SAID OPPOSITE DIRECTION IN SAID ONE LANE AND PERMITTING TRAFFIC IN SAID OPPOSITE DIRECTION IN THE OTHER LANE OF SAID TWO ADJACENT TRAFFIC LANES AND PROHIBITING TRAFFIC IN SAID ONE DIRECTION IN SAID OTHER LANE IN RESPONSE TO MEASUREMENT OF SUBSTANTIALLY EQUAL TRAFFIC IN THE RESPECTIVE DIRECTIONS AND MEANS FOR LIMITING THE CONTROL OF AN INITIAL CHANGE FROM THE LIKE CONDITIONS ON THE ADJACENT INNER LANES TO A CHANGE AFFECTING ONLY THE INNER LANE MOVING OPPOSITELY TO ITS ADJACENT OUTER LANE. 